Flooring is bought by the box, and you always buy more than the bare room area.
Standard waste
For a straight layout in a simple rectangular room, add about 10 percent. This covers cuts at the walls, the odd damaged plank, and a few spares for future repairs.
When to add more
Diagonal layouts, herringbone, long narrow rooms, and rooms with many corners or angles all waste more. Lean toward 15 percent for those.
Buy by the box and keep spares
Round up to whole boxes, and keep at least one spare. Matching a discontinued product or a different dye lot later is often impossible, so a small overage now saves a mismatched repair later.
Work out your boxes. Flooring Calculator →
Common questions
How much extra flooring should I buy?
About 10 percent for a straight layout, 15 percent for diagonal or complex rooms, plus spares.
Why buy by the box?
Flooring is sold in whole boxes, and keeping a spare box lets you match repairs to the original.
More Calculators
Concrete New
Enter slab dimensions. Result rounds up with a 7 percent waste allowance.
Gravel New
Enter the area dimensions and depth. Result rounds up with a 5 percent waste allowance.
Mulch New
Enter the bed area and depth. Result rounds up with a 5 percent allowance.
Topsoil New
Enter the area and depth. Result rounds up with a 5 percent allowance.
Paint New
Enter total wall area and coats. Result rounds up to whole units.
Flooring New
Enter room area and the coverage printed on the box. 10 percent waste added.
Tile New
Enter the area and one tile size. 10 percent waste added.
Drywall New
Enter total area to cover. 10 percent waste added.
Paver New
Enter the patio size and one paver size. 5 percent waste added.
Sand New
Enter the area and depth. 5 percent allowance added.
Roofing New
Enter the roof surface area. 10 percent waste added. Three bundles per square.
Insulation New
Enter area to cover and the coverage printed on the package. 5 percent added.
Fence New
Enter total fence length and post spacing.
Sod New
Enter the area to cover. 5 percent allowance added.
Grass Seed New
Enter area and seeding rate. Default rates suit a new lawn.
Fertilizer New
Enter area, target nitrogen rate and the first number on the bag.
Cubic Yards New
Enter length, width and depth. No waste added.
Square Footage New
Enter length and width.
Board Foot New
Enter board dimensions and quantity.
Material Cost New
Enter quantity, unit price, tax and delivery. Figures are in your own currency.